Rear brake drum problem

Here is my dilemma, I took a 8.25 rearend out of a 74 dart 4 door and put it in my duster. I was going to replace the rear brake shoes and when I ordered them, they were too small. The 2 sizes I saw are 10x2.5 and 9x2. I measured the rear shows that came off the rearend and they are 10.5x2. Could this rearend be out I something else? Or what year make and model do I need to ask for? I find it hard to believe they used a different rear on a 4 door. Help is appreciated.